A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C In the next decade 2010-2020 Prepared by the antarctic research, a european network ARENA for astrophysics consortium in fulfilment of the work programme of the EC-FP6 contract RICA 026150 Silent with star-dust, yonder it lies - What pilgrims travel the Winter Street? The Winter Street, so fair and so white; Are they not those whom here we miss Winding along through the boundless skies, In the ways and the days that are vacant below? Down heavenly vale, up heavenly height. As the dust of that Street their footfalls kiss Faintly it gleams, like a summer road Does it not brighter and brighter grow? When the light in the west is sinking low, Steps of the children there may stray Silent with star-dust! By whose abode Where the broad day shines to dark earth sleeps, Does the Winter Street in its windings go? And there at peace in the light they play, And who are they, all unheard and unseen - While some one below still wakes and weeps. O, who are they, whose blessed feet Pass over that highway smooth and sheen? Miss Edith Matilda Thomas (1854-1925) Table of contents Table 2 A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C (2010‑2020). Table of contents executive summary 6 1 approach and scope 12 1a Context 15 1b Brief historical overview 15 • Windows into geospace 16 • First steps of photonic astronomy in Antarctica 16 • Super seeing conditions on the Antarctic plateau 17 • Towards an observatory at Dome C 19 1c How ARENA worked 2 arena deliverables 24 3 site quality assessment 28 3a Available data 29 • Precipitable water vapour (PWV) 29 • Sky brightness at infrared wavelengths 30 • Optical sky brightness, fraction of clear nights, and visual extinction 30 • Temperature and wind profiles 30 • Seeing e0 30 • Outer scale L0 2 30 • Boundary layer and Cn(h) profiles 31 • Coherence time t0 and isoplanatic angle q0 31 • Additional note concerning day-time observation conditions 32 3b What is needed to finalize the site characterization at Dome C 4 astrophysics at dome c 34 36 4a Wide-field optical and infrared astronomy 36 • Working group activities 36 • Science and context 37 • Dome C potential 37 • Science cases 39 • Instrumental requirements 40 • Roadmap and funding 42 4b Submillimetre-wave astronomy 42 • Working group activities 42 • Submillimetre astronomy: science and context 43 • Dome C potential and atmosphere transmission 44 • Science cases for submillimetre/far-infrared astronomy at Dome C 44 • Telescope requirements 45 • Roadmap and funding 46 4c Optical and infrared interferometry 46 • Working group activities 46 • Science and context 47 • Dome C potential 3 .A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C (2010‑2020) 47 • Instrumental requirements 49 • Conclusion and roadmap 50 4d Long time-series photometric observations 50 • Working group activity 50 • Science and context 50 • Potential of Dome C 51 • Science cases 53 • Instrumental projects for time-series observations 54 • Roadmap and funding 56 4e CMB experiments 56 • Precision CMB measurements: the unique potential of Dome C 58 • Proposed projects 60 • Feasibility 62 4f Solar astrophysics 62 • Working group goals, activities and organization 62 • Solar astrophysics in the space and ground context 63 • Dome C unique assets for solar observations 64 • Solar science cases 65 • Proposed facilities and infrastructure 66 • Logistic footprint on the Concordia station 66 • Conclusions 5 logistics and polar constraints 68 5a Astronomy at Dome C and logistics 70 5b Plan for the installation of a large instrument 6 public outreach 72 6a Introduction 73 6b ARENA leaflet 74 6c ARENA public outreach 75 6d Recommendations for future activities 7 funding and manpower requirements 76 7a Cost and funding 80 7b Personnel and training 8 synthesis of the roadmap and final recommendations 82 annexes 86 Aa Contributors to the ARENA roadmap 91 Ab List of instruments at Dome C past, in operation, or being set up in 2009 92 Ac List of abbreviations acknowledgements 95 references 95 Table of contents Table 4 A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C (2010‑2020). 5 . Executive Summary Executive 6 A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C (2010‑2020). Executive Summary This document, prepared stronomers have always sought the the conditions on the Antarctic plateau. best possible observing conditions. ARENA created the impetus necessary to with the contributions of The inner Antarctic continent is the form international consortia in charge of Awildest, coldest, and driest desert on earth, preparing detailed studies (Phase A and B) more than 100 scientists offering an almost pristine nature without of at least a couple of the proposed pro- and engineers from Europe human contamination, or even faunal or jects; consortia that could possibly under- floral presence. It is therefore, in essence, an take their construction before the end of and Australia involved outstandingly appealing area to explore for the coming decade, 2010-2020. the construction of major astronomical fa- in Antarctic astronomy, cilities of the future. Astronomers have for Preliminary site assessments and atmos- presents a roadmap decades been attracted by this opportunity. pheric modelling by several expert teams, Several pioneering attempts have been primarily from Australia, France, and Italy, for the development made to set up increasingly sophisticated have demonstrated that this region offers instruments over the last 40 years encom- exceptional conditions for astronomy of European astronomy passing a wide range of techniques and mainly thanks to the cold, dry, and calm and astrophysics in scientific goals. The only major astronomi- atmosphere. The atmosphere above the cal facility so far established is at the US highest spots of the Antarctic continent the Antarctic continent, station Amundsen-Scott, right at the geo- offers the best conditions on earth to and more specifically, graphic South Pole station, and named the investigate astronomical objects at high Martin A. Pomerantz Observatory in tribute angular resolution in the near thermal IR at the Concordia station to one of the most active astronomers in and submillimetre-wave ranges. The high Antarctica over the last half century. latitude location allows very long conti- (Dome C) in the coming nuous night-time photometric observa- decade (2010‑2020). France and Italy have recently joined the tions, which are essential for the study of effort: they have built and, since 2005, periodic variability of celestial objects. In It is based on the work operate year-round a multidisciplinary several well-identified domains («niches») station at Dome C called Concordia, one the Antarctic plateau may even compete carried out during of the highest domes on the Antarctic with space missions, but at a much lower the period 2006‑2009 Plateau, located about 1,200km from cost, and with the invaluable bonus of the sea coast at a latitude of about -75° using the most advanced technologies. within the framework and an elevation of 3,202m. Dome C is an extremely promising location for the The ARENA network has identified six of the ARENA network. establishment of the first European astro- particularly promising astrophysical areas nomical observatory in Antarctica, which with well-defined research programmes. eventually could become a major item of Taking into account the constraints of lo- international research infrastructure. gistics and environment, the network has been able to outline the top-level requi- To explore this opportunity in all its as- rements for the instrumentation able to pects, a network, ARENA, was created un- address these programmes. der the auspices of the European Com- mission. ARENA has had as a goal the They are, i) wide-field, extremely sensitive investigation of the scientific prospects imaging and spectro-imaging in the near of and the possibility of implementing an and thermal infrared (2.3-4µm) with a astronomical observatory at Concordia, 2.5m-class telescope (the PLT project), and to document a suite of instrumental ii) extremely sensitive submillimetre-wave projects that could benefit greatly from imager with a collecting area equivalent 7 .A Vision for European Astronomy and Astrophysics at the Antarctic station Concordia, Dome C (2010‑2020) to a 25m dish (project AST), iii) near IR beyond 2.3µm where observations are a catalogue of source calibrators in the interferometry for the detection of exo- normally hampered by the strong thermal far-southern sky, and attempt several planets and exozodiacal light (the ALAD- background emission of the sky from the science observations of the Sun and of DIN project), iv) a set of smaller dedica- ground. Thanks to the exceptional seeing star formation. ted instruments (some of them already conditions above the turbulent layer, Dome in the construction on-site) for planetary C is an ideal site to make large-scale, high Finally, this roadmap provides a vision transits, stellar variability, asteroseismo- angular resolution, extremely deep ima- for an Antarctic Submillimetre Telescope logy, and infrared imaging photometry, v) ging surveys in this wavelength regime. (AST) project. This could be a large teles- cosmic microwave background experi- cope facility consisting of a 25m diameter ments (the QUBIC project) and, vi) high The PLT (Polar Large Telescope) project class, single-dish at Dome C, or equivalent angular resolution solar measurements is the result of extensive discussions collective area achieved with a network (the AFSIIC project). between Europeans and Australians of medium-size radio telescope antennas, to propose a realistic, albeit ambitious, operating at submillimetre wavelengths A series of recommendations have been project for such a telescope with a and offering unique science possibilities. Its drawn from the discussions held during 2.5m aperture.